JSFiddle - React, Tailwind, and code Playground

HTML

<form>
  <select name="country" id="country" class="form-control action">
      <option value="">Select Country</option>
      <option value="usa">USA</option>
  </select>
  <select name="state" id="state" class="form-control action">
      <option value="">Select State</option>
      <option value="cal">California</option>
  </select>
  <select name="city" id="city" class="form-control">
      <option value="">Select City</option>
  </select>
</form>

JavaScript

$('.action').change(function() {
	var formValues = $(this).closest('form').serialize();

	$.ajax({
      url: "fetch.php",
      method: "POST",
      data: formValues,
      success: function (data) {
          $('#' + result).html(data);
      }
  });
});